What makes an electric car special.
Electric motors impress with their powerful acceleration.
Compared to a combustion engine, the power of an electric drive is unleashed even more dynamically. When driven, its full power is delivered without delay.
The electric car battery replaces the fuel tank.
Drive with electricity, instead of burning fuel. An electric car does not have a petrol or diesel tank. It has an electric car battery, well protected to withstand an accident, along with a charging system.
Recuperation charges the battery during braking.
Cars with an electric motor have a regenerative brake system. Unlike conventional brake systems, it recovers energy. This is known as energy recovery or recuperation.
The BMW electric car battery. Good to know.
Capacity, charging power or weight. Lots of terms are used with electric car batteries. A brief overview.
Electric car batteries are essentially energy packs.
Batteries of electric cars are mobile energy stores. Electric car batteries consist of a large number of battery cells. These cells are charged with electricity from the charging station and transfer it to the electric motor. The amount of energy an electric car battery can store in kilowatt hours (kWh) is calculated from the number and energy content of the cells, often expressed in the form of its capacity. The charging power in kilowatts (kW) indicates how quickly an electric car will charge at the charging station.
An electric car battery is very powerful.
An electric car battery works in principle rather like a mobile phone battery, although it is much bigger and more powerful, with a longer service life. An intelligent heat management system keeps the electric car battery at an optimum operating temperature. On the one hand, this protects it from excessively high temperatures when high power is called for when driving. On the other hand, it ensures the shortest possible charging times for your BMW.
Battery weight is linked to its range.
The larger the electric car battery, the more energy it can store. This increases its range, but also its weight. An electric car battery can weigh several hundred kilograms. Continuously improved technology and increasing energy density are extending the range without adding more weight to the electric car battery. BMW is also contributing to this with its Battery Cell Competence Centre.
A long service life is the inherent value of an electric car battery.
Like a combustion engine, the electric car battery is the most valuable component of a BMW. Among other things, the price of an electric car battery depends on its capacity. In short, the more energy an electric car battery can store, the more it costs. However, drivers can have a positive impact on the service life of an electric car battery by adapting their own driving behaviour. Built-in functions also help to protect it.
How to positively impact the service life of your electric car battery.
An electric car battery has been developed with the greatest care. However, range and charging performance decline somewhat over time in line with a normal ageing process. This is known as the State of Health (SoH). This term expresses the maximum energy capacity of a used electric car battery compared to a new one. A lower SoH equates to a shorter range. But you can maximise the service life of the battery with careful treatment and cautious driving style.
Recommendations to optimise the service life of your electric car battery.
Gentle, slow charging.
Prefer to charge electric car batteries more slowly at wallboxes, AC or DC charging stations with a maximum of 100 kW. It is best to keep High-Power-Charging (HPC) at quick charging stations for longer journeys.
Plug-in only if required.
Only charge when you need to – and not after every journey. When parking your car, low to medium states of charge are better for the service life of the electric car battery.
Charge to 100% for long journeys.
A state of charge of between 10% and 80% for everyday driving is recommended for your electric car battery. Only charge to 100% for longer journeys, preferably just before you set off.
Set a charging target for everyday driving.
Ideally avoid full charges in everyday driving. BMW recommends a charging target of at most 80%.
Avoid empty batteries.
Charge your battery before its state of charge falls below 10%. Ideally maintain the state of charge within the recommended range of 10% to 80%.
Moderate driving styles go easy on the battery.
Accelerate moderately and drive in an anticipatory manner at a steady speed to look after your electric car battery. That also means fewer visits to charging stations.
Keep consumption low.
Avoid carrying unnecessary luggage or roof boxes. This will reduce your energy consumption and ease pressure on the electric car battery.
Moderate temperatures are ideal.
Preferably park your electric car in the shade or in a garage in hot weather. Especially if you plan to park it for a long period of time.
Moderate battery charge state over long stationary periods.
An electric car battery discharges energy very slowly when it is parked. Therefore, it's not advisable to connect your car to a charging post before longer stationary periods, for example when you’re going on holiday. The ideal state of charge for the battery is 30-50%.
How the electric car battery retains its high energy level.
An electric car battery is designed for all kinds of everyday driving situations but is subject to physically induced ageing. One aspect of its ageing is time-related, by its age in years. The more consistently high states of charge and battery temperatures are avoided when the vehicle is parked, the lower is its time-related ageing. The second aspect of ageing is significantly influenced by the number of charging and discharging cycles. This is what is known as cyclic ageing. It is reduced, among other things, by an anticipatory driving style and moderate charging power.
Long-term experience using the example of the BMW i3.
The durability of BMW electric car batteries is demonstrated by our pioneering electric car, the BMW i3. We have been observing the ageing process of its electric car battery since 2013. And even before that, during the development of the BMW i3, we analysed the ageing process by simulating it in complex driving and charging tests.
Best prerequisites for newer BMW generations.
Compared to current models, the early BMW i3 models had very small electric car batteries. But, thanks to technical advances and bigger batteries, newer BMW electric car generations are once again better equipped to deal with ageing. However, as this is affected in individual cases by many factors, it is impossible to make a blanket statement about the ageing process of individual vehicles.
The structure of an electric motor. Explained simply.
How an electric drive works.
An electric motor converts current into movement. It has two key components: the rotor and stator. As its name suggests, the rotor rotates. This occurs by the interaction of the magnetic field of the rotor and stator. The rotor’s magnetic field is generated by magnets or current, depending on the type of motor. The electric motor transmits this turning motion to the wheels through a 1-speed transmission. When you look at the driving cycle (WLTP), the efficiency of an electric motor is more than three times that of a combustion engine. BMW electric vehicles are often fitted with very efficient current-excited synchronous motors, so-called CESMs.
Benefits of current-excited synchronous motors (CESM).
A core competence at BMW is its widespread use of CESMs. These motors are distinguished by dispensing with the use of “rare earth elements” in the rotor. Compared to other types of motor, CESMs feature efficient power characteristics and also accelerate well at high speed. This is useful when overtaking on the motorway. CESMs also have efficient consumption. As they magnetise the rotor with current, they either work efficiency-optimised or power-optimised, depending on the situation.
Benefits of permanent-magnet-excited synchronous motors (PMSM).
A PMSM design of electric motor boasts a high power density. Within a given space, it can generate comparably high levels of power. Technically, it differs from an CESM in that it generates the magnetic field in the rotor differently, by producing it by permanent magnets. A PMSM is therefore ideal for integration into the transmission of Plug-in Hybrid Electric Vehicles (PHEVs) and M-PHEV (BMW XM) vehicles.
Simple engineering. Simple to drive.
A BMW electric car accelerates directly. Without the need to use the clutch and shift gear. Unlike a combustion engine, an electric motor makes its power available even more immediately. Its torque is high and almost constant in the lower speed ranges. At higher speeds, the electric motor can summon its full power at any time. Unlike with a combustion engine, its speed does not need to be adjusted by changing gear.
Driving an electric BMW. A unique experience.
An electric BMW drives relaxingly quietly, yet at the same time in a familiar way. When you step on the pedal, it accelerates immediately, powerfully and with excellent modulation. And there is a precise pedal feel when braking. It also has a low centre of gravity due to the battery being located in the underbody. And your BMW also boasts excellent roadholding.
Why an electric car accelerates so quickly.
The use of a 1-speed transmission means your electric BMW accelerates seamlessly without shifting. Torque is immediately there when you depress the accelerator pedal. When you take your foot off the pedal, your BMW slows down just as readily, depending on your preference and your selected energy recovery setting.
How a BMW brakes with intelligent recuperation.
The brake system of an electric BMW analyses braking situations for maximum efficiency and makes use of the full recuperation potential of the electric motor. If need be, the conventional brake system is also activated. This intelligent interplay recovers maximum energy, is gentle on the brakes and reduces brake particle emissions.
Questions and answers about batteries and electric motors.
More information.
Electric range.
Our electric cars have a range that easily allows you to travel longer distances. The route planner will show you where you can charge your car while on the road.
Charging at home.
Charge your electric car or plug-in hybrid overnight or between trips. Start your day ready to go and conveniently adapt the charging of your electric BMW to your everyday life
1 The stated values are based on the mandatory WLTP measurement procedure. The real life values depend on various factors, e.g. cargo weight, driving style, route, weather conditions, auxiliary electrical consumption (including air conditioning), tires, battery state of health.